Added support for literal number suffices (valid suffices are: 'r' for rational, 'f' for floating-point and 'i' for integer')

Example:
	say 255r/2r;    # 255/2
	say 255f/2f;    # 127.5
	say 255i/2i;    # 127

Also, with this feature, the initialization of numbers has been improved. (now Number.new('0xffff') works)